BBV's Room Measurement Saga Continues...

Bad. Try a 'golden rule' positioning. In a room and set-up like yours, my preference would be for the speakers a bit closer together than you seem to have.

As a more general comment, I'm surprised that you resort to EQ before optimizing the room sound with more traditional means, especially room placement. Have you tried CARA?

 

Thats approx - I will put the exact measurements tonight. I think it might have been 1.6m and 2m. Its harder to get the speakers much closer together unless I move them further out into the room.

Cara? I positioned by ear after trying a number of different options.

 

Hi,

Spacings like this, together with the usual around 1m or thereabouts will maximise LF response non-flatness.

A hint here. When using W.A.S.P. for speaker setup I found that the zones of neutrality often correspond closely to a spacing fo the speaker from surfaces related to the ratio aureum (1.618:1), so try, starting with the ceiling/floor distance to divide the dimension by 2.618 and seek to locate the speakers there.

So, in a room 2.4m high (main modes ~ 150 & 300hz), 4m wide and 6m long attempt to place the LF source at around 92cm high and around 148cm from the long wall (I would always place speakers along the long wall) suitably centered. Having the L/R speakers placed symmetrically in the room the limits the influence of the modes along the longest room dimension.

Other usages are possible.

Cara-Quick is usually a good tool to estimate the development of room resonances.

http://www.cara.de/ENU/index.php?load=quick.html

Ciao T

 

Tenson, call it points scoring if you like. Do I want to help Nick? Well given some of his past comments, I think a gentle nudge in the right direction is fair enough. What I don't want to see is a thread where people seem to be going around like headless chickens - that's a waste of your time and mine.

I think Markus has summed it up very well. I think the use of EQ prior to optimisation in the room itself is a very poor solution. That is what I am getting at, and what I am asking you to explain to Nick.

You will see from the graph that there is a suckout at 60hz (where the 2nd harmonic should be) and another at 120hz (where the 3rd Harmonic should be). So the listening position is in a null. Or of course the speakers are.

Nick what are the precise dimensions of that room, including the kitchen area if it is open?

 

Image of plan attached.

In all fairness Tenson did suggest moving the speakers before eq but I didnt want to go along with it so I think the blame should be apportioned totally to me.

Due to access required to the outside door and the inside cupboards as well as all the equipment along the outside wall the options for placement are limited. The mb2s are also very sensitive to toe-in.

I will pinpoint the speaker and listening position tonight and post it up, as well as the speaker sizes and driver positions. I am guessing the ceiling is at least about 3.5m.


.

 

On a completely different note (apologies) what software are you using for the building plans?

 

I didnt - its the landlords plan I downloaded from the website.

 

Hi,

Who is the landlord and how much does a place like this cost in rent (PM me)? Could I (as lowly NHS Worker) afford it?

I am looking for somewhat more presentable digs...

Ciao T

 

I just thought thay you may be interested in my RT-60 curve.

Black trace is our target curve, blue one is base curve (empty room, no add-on acoustic treatment, no wooden floor), red curve shows how the room responded after ACS diffusors, wooden floor and sand stone were added. Green curve is the most recent one. It is still not perfect, but we are working on it.

 

Nick,

when you get home, try moving the speakers a foot further into the room. Also can you tell us where your listening position is (ie how far from the back wall of the kitchen)?

Thorsten is spot on in that you want to get the distances from boundaries as different as possible and using the golden ratio will help to achieve that in the space that you have.

 

I will put the measurements tonight. It would be more easy to move the chair given the mb2s are on townshend platforms

 

The room measurements are exactly correct. Height is 2.75m.

Both speakers are 1.75m from the rear wall and the L is 1.33m from the side wall and the R is 1.17m from the side wall - there is a little more space open behind the R speaker as it opens out to the door. All measurements to mid part of front baffle.

Listening position is slap back in the centre and my ears are 1.4m from the rear wall such as it exists.

Driver mid point heights:

bass 0.61m
mid 0.88m
treble 1.03m

 

If I use the xdb should I put it next to the mb2 but upside down to give slightly different modes and therefore average out a little or does this introduce more problems than it solves?

 

Come on guys I put the room dimensions up - any response? SM?